1. Field of the Invention
The invention is directed to a method of producing 2,2-dimethyl-3-hydroxypropyl-2,2-dimethyl-3-hydroxypropionate (HPN). More particularly, the invention is directed to a method of producing HPN from the by-product stream of a neopentyl glycol (NP) production process.
2. Description of the Related Art
Various processes for the production of neopentyl glycol have associated with them the production of undesirable by-products which are often burned as wastestream. Heretofore, numerous attempts have been made to recover neopentyl glycol from by-product streams or to convert by-product stream components into desirable products.
Duke, Jr., et al, U.S. Pat. No. 3,340,312 discloses a process wherein mixtures of hydroxypivaldehyde and isobutyraldehyde can be hydrogenated in the presence of a copper-chromium oxide hydrogenation catalyst to yield isobutanol and neopentyl glycol.
Wright, U.S. Pat. No. 3,939,216 discloses a process for recovery of neopentyl glycol from a waste streams containing neopentyl glycol and water by contacting the by-product stream with isobutyraldehyde and subsequently separating this by-product stream into an organic stream containing neopentyl glycol and isobutyraldehyde and an aqueous stream essentially free of neopentyl glycol.
Holzrichter, U.S. Pat. No. 4,474,939, discloses eutectic mixtures of diols selected from the group consisting of neopentyl glycol, trimethylpentane diol, cyclohexanedimethanol, and 1,6-hexanediol.
Heretofore, there has been no process for the production of HPN and/or eutectic blends of neopentyl glycol and HPN from a by-product stream containing neopentyl glycol, hydroxypivalic acid (HPAD) and HPN.